High pressure fluid supply and quick action valve

ABSTRACT

A quick action firing assembly for charging and sudden release of gas under pressure in a seismic energy generator for offshore subsurface exploration, for example, comprising a hollow, elongated valve having equal and opposite surfaces and means for charging the generator through the valve with high pressure gas and simultaneously applying equal forces in opposite directions to the valve whereby a minimum of force is required to open the valve.

United States Patent Umphenour et al.

[4 1 Sept. 30, 1975 HIGH PRESSURE FLUID SUPPLY AND QUICK ACTION VALVEInventors: Charles F. Umphenour; Reynaldo Calderon, both of Houston,Tex.

Assignee: Texaco Inc., New York. N.Y.

Filed: Jan. 28, 1974 Appl. No.: 437,117

Related US. Application Data Division of Ser. No, 224,735. Feb. 9 1972,Pat. No. 3.800.832.

US. Cl. 137/625-26 Int. Cl. FIGK 11/00 Field of Search... 251/282;137/625.25,625.26,

References Cited UNITED STATES PATENTS Livers ct al. l37/625.25 x

Collins l37/625.25 X

2.893.428 7/ l 959 3.074.433 l/l963 Stark 251/282 X 3684.238 8/1972Michcllone 251/282 X Primary Examiner-Martin P. Schwadron AssistantEruminerRobert J. Miller Attorney. Agent. 0" FirmThomas H. Whaley; CarlG. Ries; Theron H. Nichols 5 7] ABSTRACT A quick action firing assemblyfor charging and sudden release of gas under pressure in a seismicenergy generator for offshore subsurface exploration, for example,comprising a hollow, elongated valve having equal and opposite surfacesand means for charging the generator through the valve with highpressure gas and simultaneously applying equal forces in oppositedirections to the valve whereby a minimum of force is required to openthe valve.

5 Claims, 2 Drawing Figures 7 HIGH PRESSURE FLUID SUPPLY AND QUICKACTION VALVE This is a division of application Ser. 'No. 224,735, filedFeb. 9, 1972, 'now Pat. No. 3,800,832.

BACKGROUND OF THE INVENTION Broadly the present invention relates toseismic exploration and to an improved pneumatic marine seismic energysource for the introduction of seismic energy into water from a floatingvessel for supplying compressed air and having a geophysical crewthereon for exploring earth layers and formations underlying bodies ofwater as oceans, seas, lakes, rivers, or the like. More particularlythis invention pertains to a method and at least one mechanism forcarrying out the method,one exemplary mechanism being a quick actionfiring assembly for efficiently charging a seismic energy generatorchamber with a high pressure gas and likewise for quickly andefficiently releasing'the high pressure gas from the chamber with anexpenditure of a minimum of energy or force While the method andapparatus of the invention are applicable for many purposes as will beset forth further below, they are illustratively disclosed and describedas applied to underwater sound instrumentation such as oceanographicequipment and systems that are employed in seismic exploration of theworlds crust under and adjacent to bodies of water.

Since water is such a good sound conductor, it is unnecessary togenerate sound waves right on or in the ocean floor; they can beproduced in the water near the surface. The pressure waves travel downthrough the water to the ocean floor and are reflected as in the usualecho-sounding techniques. However, these waves also penetrate into theocean floor and are reflected from the sub-strata. These acousticalwaves also propagate horizontally through one or more geological strataand may be recorded at a distance from the source, thus providing usefulrefraction data on the stratum or strata involved.

Although explosives for marine seismic work can put large amounts ofenergy into the water and obtain great depth of penetration, they dohave drawbacks; they are dangerous to handle and use, and in some areassuch as congested harbors, they cannot be used at all. Also, each shotis very expensive and can run into many thousands of dollars per survey.Explosives tend generally to concentrate substantial amounts of theirenergy output into higher frequency components which may not bedesirable for many purposes; whereas, the sound impulse generationmethod and apparatus which the present invention is used on can beadjusted over a large amplitude range and adjusted in frequency so as toprovide the desired spectrum distribution of sound frequencies for thepurpose at hand.

The present invention is illustratively described as embodied in adevice capable of emitting a large amount of acoustical energy intowater in the form of a clear, repeatable pulse, the frequency andamplitude of which may be readily averred. These powerful sound impulsesare well adapted for use in seismic exploration systems and also can. beused to advantage for other purposes. A

Seismic surveys which are conducted over water covered areas use variousmethods for generating seismic energy as by the detonating ofconventional powder or dynamite, or gas mictures, electrical dischargeof sparks to ionize a portion of the water surrounding the electrode, orsuddenly releasing a container of high pressure air underwater forgenerating a large seismic or pressure wave signal. These seismicsignals are reflected from subsurface geological formations andstructures and are received by seismometers and recorded.

In all methods utilized, it is customary to tow one or more detectorsthrough the water in the vicinity of the sound source to detect thesignals that are reflected from the various subsurface formations andstructures. The detected signals are recorded on suitable equipmentcontained on the towing vessels, either in the form or analog or digitalsignals. Also, at times thesignals are recorded as variable area signalsto provide a profile of the surveyed area. The latter recording issimilar to those contained with conventional depthsounding equipment.

All of the above seismic methods and devices have I variousdisadvantages and thus none is completely suitable for use in allcircumstances. The handling of an explosive material is, of course,dangerous as mentioned previously, wherein the explosions themselvestend to kill much marine life, an example of a seismic explosive devicebeing disclosed in U.S. Pat. No. 2,877,859. Also, in the case ofdynamite two separate vessels are required; one for handling thedynamite and the other for the recording equipment This, of course,increases the cost of the survey.

Aside from the operational advantages over conventional dynamitesurveys, the disclosed system affords better data acquisition throughthe effective and quicker acting pressure release valve having less backpressure to work against and requiring less power or voltage to actuatethe actuating solenoid for firing a seismic acoustical energy generatoror air gun.

The use of explosive gas mixture solves some of the problems that arisewith dynamite, since explosive gas mixtures do not kill as much marinelife, a further example being disclosed in U.S. Pat. No. 3,620,327.Normally, gas mixtures can be stored as separate, nonexplosive gases onthe same vessel that contains the recording equipment. Thus, the needfor an additional vessel or the possibility of killing marine life isreduced. While one disadvantage of gas. type sound sources is therelatively short life of the flexible container or sleeve in which theexplosive gas mixtures are detonated, conservation of the presentenvironment is one of the principal problems.

In sound sources employing an electrical discharge, it has beencustomary to discharge a bank of capacitors charged to a high voltagethrough a single electrode or multiple parallel electrodes and a groundplate. When the capacitor bank is discharged into the water by theelectrodes and ground plate the pressure bubble is produced at eachelectrode tip, for the ground plate serves as a return for theelectrical energy. The pressure bubble produces the desired seismicimpulse while the ground adds nothing to the magnitude of the outgoingacoustical wave. In fact, only 3-5 percent of the total electricalenergy available in the capacitor bank is converted to useful acousticalenergy in the water. Further, many spark electrodes in parallel may beused simultaneously as disclosed in U.S. Pat. No. 3,613,823.

DESCRIPTION OF PRIOR ART While compressed pneumatic guns as disclosed inUS. Pat. Nos. 3,276,534 and 3,379,273 and assignees application Ser. No.160,693, filed July 8, 1971, each has a passage through the plunger forthe passage of air, none have the feature of equal and opposite areasnormal to the longitudinal axis of the plunger for insuring a minimumrequired force to actuate the plunger to release the compressed air. Themost pertinent disclosure, assignees above identified application,illustrates an air gun in which a larger area and resultant forcetending to maintain the plunger closed, in addition to the spring, mustbe overcome to open the valve, whereas the instant invention has onlythe force of the spring to overcome, resulting in a much fasteroperating seismic energy generator requiring less power or voltage tooperate the solenoid for actuation of the valve.

OBJECTS OF THE INVENTION A primary object of this invention is toprovide a method for charging a chamber with high pressure fluid and forquickly releasing the fluid with a minimum force.

Another primary object of this invention is to provide a device forcarrying out the above method comprising a valve assembly for charging achamber with high pressure fluid and simultaneously applying equal andopposite forces to the valve for requiring a minimum of valve openingforces.

Another object of this invention is to provide a hollow, spring loadedvalve for supplying gas under pressure to a chamber and a means forapplying an equal force in both directions to the valve whereby aminimum force is required to open the valve.

A further object of this invention is to provide a valve having equaland opposite areas and means for applying a fluid pressure fordeveloping equal and opposite forces on the valve so that a minimumforce is required to open the valve.

Still another object of this invention is to provide an air gun firingassembly for a seismic energy source which is easy to operate, is ofsimple configuration, is economical to build and assemble, and is ofgreater efficiency for charging a seismic energy generator and forsuddenly releasing the gas under high pressure for offshore subsurfaceexploration.

Other objects and various advantages of the disclosed firing assemblyfor an acoustical energy generator for offshore subsurface explorationwill be apparent from the following detailed description, together withaccompanying drawing, submitted for purposes of illustration only andnot intended to define the scope of the invention, reference being hadfor that purpose to the subjomed claims.

BRIEF DESCRIPTION OF THE DRAWING The drawing diagrammaticallyillustrates by way of example, not by way of limitation, one form of theinvention wherein like reference numerals have been employed to indicatesimilar parts in the several views in which;

FIG. 1 is a schematic sectional view of an embodiment of the new seismicenergy generator having the new firing mechanism therein; and

FIG. 2 is a sectional view at 22 on FIG. 1.

DESCRIPTION OF THE PREFERRED METHOD OF THE INVENTION The inventiondisclosed herein, the scope of which being defined in the appendedclaims, is not limited in its application to the details of constructionand arrangement' of parts shown and described for carrying out themethod, since the invention is capable of other embodiments for carryingout other methods and of being practiced or carried out in various otherways. Also, it is to be understood that the phraseology or terminologyemployed herein is for the purpose of description and not of limitation.Further, many modifications and variations of the invention ashereinbefore set forth may occur to those skilled in the art. Therefore,all such modifications and variations which are within the spirit andscope of the invention herein are included and only such limitationsshould be imposed as are indicated in the appended claims.

This invention comprises both a method and a device for carrying out themethod of charging a chamber with high pressure gas and for quicklyreleasing the gas with a minimum force.

This method comprises the steps of:

1. charging the chamber with high pressure fluid through a hollow closedvalve, and

2. simultaneously applying equal forces in opposite directions to thevalve so that only a minimum of force is required to open the valve forquick release of the fluid.

Step 2 comprises in greater detail:

1. applying fluid under pressure to equal areas of the valve in oppositedirections simultaneously with charging of the chamber.

Modifying the second method step or adding a third method stepcomprises:

a. cutting off flow of high pressure fluid to the chamber simultaneouslywith applying equal forces in opposite directions to the valve wherebyonly a minimum force is required to open the valve.

DESCRIPTION OF THE PREFERRED EMBODIMENT While various articles may beutilized for carrying out the above method of the invention, thepreferred embodiment comprises a quickaction valve assembly for suddenrelease of gas under pressure from an inletexit port of a chamber of aseismic acoustical energy generator. Likewise, this valve assembly isutilized also for charging the high pressure chamber.

The disclosed firing assembly comprises, as shown in FIG. 1, acylindrical housing 10 for containing the firing assembly and forattaching to a conventional acoustical pneumatic energy generator 11.

A typical seismic wave generator 11, FIG. 1, is lowered into thesurrounding earth, marsh, or water, offshore or down in a conventionalshot hole filled with water, for example. While FIG. 1 illustrates theposition of the seismic energy generator in the vertical position forshothole seismic surveying when being towed for offshore subsurfaceexploration, the generator would be rotated clockwise The circularhousing 10, FIG. 1, has an inlet 12 at the top connected to a suitablesource of high pressure fluid, such as air, which is supplied to mainpassage 13 for distribution to the air gun l1, and particularly to ahigh pressure air chamber (not shown) at the bottom of the air gun andto..a.firin g mechanism at the top of the air gun. I

The air gun has a smaller chamber .14 having an inletexit port oropening 15, outlet passages 16 andg17, and exhaust port 18 from whichthe expanding air rushes out to the surrounding water.- --T he chamberinletexit port is shown closed by the .,new hollow plunger valve 19. 1 a

The hollow plunger valve 19 comprises two parts, a

larger hollow lower bodyupper part 19a for. enclosing a spring 20 and asmaller hollow part or plunger. stem 19b screwed into the plungerbody.The body 1-9a of the plunger is slidable .over a stud; 21 screwed inplunger valve guide'22- in housing 10. Thus, when the plunger valve ismoved upwardly and opened, thehigh pressure air may escape from chamber14 out through exhaust passages 16 and 1740 exit from the exhaust port18 to escape out into the surrounding water. As shown in FIG. 2, threesets of exhaust passages are preferable. The hollow plunger is shownclosing the opening and'is held in closed position'with the sprin'g'20.

l-ligh pressure air from the supply passage 13 likewise travelstransversely through a firing assembly first passage 23 to a annularsecond passage 24 around the portion 19b of the'plunger. While a sloppyfit is shown between the cylindrical portion 19b and the walls of thepassage 24','FIG. 1, leakage of the air downwardly and outwardly tooutlet passages 16 and 17 is prevented by sealing O-ringZSinth'ehousing. From there the air travels through?! l'argerp'ortion of theannular second passage 24 surrounding the "plunger larger portion 19a.Both upper and lower flat 'en ds 26 and 27, respectively, of thelarger'portion 19d of the plunger'and the flat ends 28 and 29,respectively, of the smaller portion 19b are formed to thesame'iden'tical areas, respectively, and are -normal to the longitudinalaxis of the plunger. Thus, as the air under pressure passes through the'a'nnular passage 24 around the smaller and larger portions of theplunger, and since these air passages are formed with a sloppy fit, asillustrated in FIG. 1, resulting in' negligible air resistance, the air'correspondingly arrives at both ends of each of the two valve portions19a and 19b, practically simultaneously and accordingly the forces areneutralized for actuating the plungerin either direction. Third passages30 extend from this sec- .ond cylindrical passage 24 to the interiorofthe hollow plunger 'valve 19. From, the hollow portion of I the plungerthe air passes to thechamber for charging it with high pressure air.Respective O-rings 31 and 32 for sealing are provided between the twoportions 19a and 19b of the plunger valve and in the air gun around theinlet-exit opening 15 of the chamber, respectively.

A solenoid 34 is mounted in the housing around at least a portion of theplunger and has electrical wires 35 passing to electrical plug 36 forplugging into a suitable energy source for energizing the solenoid.Further, an O-ring 33 is mounted around the end of the stud thatprotrudes into the plunger. Upon actuation of the solenoid 34, theplunger 19a is moved upwardly in plunger guide 22, the spring 20 iscompressed, and the plunger third passages 30 are sealed closed by thestud O-ring 33. ,When these latter passages are closed, no fluid isallowed to flow internally of the plunger nor to pass out of the plungerto charge the attached air gun. With equal pressure on equal andopposite plunger ends, the solenoid has to overcome only the force ofthe spring to actuate plunger valve 19 to open chamber inlet-exit port15, the friction and drag of the air passing through the passagesbeingnegligible.

FIG. 2, a sectional view of 2-2 on FIG. 1, illustrates the requirementof three sets of outlet passages and ex haust ports, 17- and 18,respectively, while only one transverse high pressure fluid passage 23is required.

Thus in operation, as high pressure fluid passes through the mainpassage 13 to charge the high presing the plunger valve againsttheopening and for sealing the opening. With the plunger in this position,eithe? equal hydraulic or'pneumatic pressure is applied to both oppositeends of both plunger valve parts and accordingly equal and oppositeforces are applied thereto, which counteracting forces maintaining theplunger at either of its position's' To fire the air gun, the solenoidis energized which then jerks with a minimum of force the plungerupwardly and away from the inletexit 'aort 15. The action of thesolenoid is'only opposed by the spring in that immediately upon upwardactua- .tion of the plunger the third passages are closed by O- ring 33,thereby cancelling out or stopping the flow of high pressure fluidthrough the center of the plunger and the pneumatic pressure maintainsequal and opposite. forces on the ends of the plunger valve. Accord-,ingly, upon actuation of the plunger upwardlythe high ration. =When theplunger. is at either of its end positions, and pneumatic forces areequalized due to being applied to both ends of the plunger, a minimum offorce is required to open the plunger valve. Thus a high pressure airsupply and quick-action valve assembly is disclosed for charging achamber having an inlet-exit portand for suddenlyexhausting the highpressure at therefrom; a

Accordingly, it will be seen that the present firing assembly for theseismic energy source for offshore subsurface exploration operates in amanner which meets each of the objects set forth hereinbefore.

While only one method and one embodiment for carrying out the method ofthe invention have been disclosed, it will be evident that various othermethods and modifications are possible in the arrangement andconstruction of the disclosed firing assembly for a seismic energygenerator for offshore subsurface exploration without departing from thescope of the invention, and it is accordingly desired to comprehendwithin the purview of this invention such modifications as may beconsidered to fall within the scope of the appended claims.

We claim: 7

1. A high pressure fluid supply and quick action valve assembly forcharging a chamber having an inlet-exit port, supply passage means tosaid chamber and exhaust passage means from said chamber comprising,

a. hollow elongated valve means having twodirectional movement along itslongitudinal axis and being spring biased in one direction against saidinlet-exit port for charging said chamber with high pressure fluid,

b. fluid pressure passage means for applying an equal force in both ofsaid directions to said hollow elongated valve means so that a minimumforce is required to open said inlet-exit port,

0. said hollow elongated valve means being movable rapidly in a seconddirection to open said inlet-exit port suddenly for exhausting said highpressure fluid therefrom,

d. said hollow elongated valve means comprises a hollow elongatedplunger slidably mounted in a housing containing said chamber,

e. said hollow elongated plunger having equal and opposite areas normalto said longitudinal axis for said equal and opposite forces to beapplied thereto,

f. said hollow elongated plunger comprising first and second hollowelongated elements having inner and outer ends, the inner end of saidsecond element being secured in the inner end of said first element,

g. a stud fixed to said housing and protruding therefrom into the outerend of said first element, and

h. a spring positioned in said first element between said stud and saidinner end of said second element for spring biasing said outer end ofsaid second ele' ment against said inlet-exit port for charging saidchamber with high pressure fluid.

2. A high pressure fluid supply and quick action valve assembly forcharging a chamber having an inlet-exit port supply passage means tosaid chamber and exhaust passage means from said chamber comprising,

a. hollow elongatedvalve means having twodirectional movement on itslongitudinal axis and being spring biased in one direction against saidinlet-exit port for charging said chamber with high pressure fluid,

b. fluid pressure passage means for applying an equal force in both ofsaid directions to said hollow elongated valve means so that a minimumforce is required to open said inlet-exit port,

c. said hollow elongated valve means being movable rapidly in a seconddirection to open said inlet-exit port suddenly for exhausting said highpressure fluid therefrom,

d. said fluid pressure passage means comprises a first fluid passagethrough the length of said hollow elongated plunger means forpressurizing and charging said chamber,

e. said hollow elongated plunger means has equal and opposite areasnormal to its longitudinal axis,

f. said fluid pressure passage means comprises a second passage to saidequal and opposite areas on said hollow elongated plunger means forapplying equal and opposite forces longitudinally to said hollowelongated plunger means,

g. said fluid pressure passage means comprises a third passagetransversely through said hollow elongated plunger means interconnectingsaid first and second passages for charging and pressurizing saidchamber,

h. actuating means,

i. said hollow elongated plunger means being responsive to saidactuating means for closing said third passage for stopping the flow ofpressurized fluid to said chamber, and

j. said housing has stud means for closing said third passage as saidhollow elongated plunger means is moved in one of said two directions onits longitudinal axis for stopping the flow of pressurized fluid to saidchamber.

3. A high pressure fluid supply and quick action valve assembly asrecited in claim 1 wherein,

a. said fluid pressure passage means comprises a fluid passage to saidequal and opposite areas on said hollow elongated plunger means forapplying equal and opposite longitudinal forces to said hollow elongatedplunger means.

4. A high pressure fluid supply and quick action valve assembly asrecited in claim 1 wherein,

a. the valve assembly has actuating means, and

b. said hollow elongated plunger means is responsive to said actuatingmeans for opening said inlet-exit port for quick release of pressurizedfluid from said chamber.

5. A high pressure fluid supply and quick action valve assembly asrecited in claim 2 wherein,

a. said hollow elongated plunger means is responsive to said actuatingmeans for opening said inlet-exit port for quick release of pressurizedfluid from said chamber.

1. A high pressure fluid supply and quick action valve assembly forcharging a chamber having an inlet-exit port, supply passage means tosaid chamber and exhaust passage means from said chamber comprising, a.hollow elongated valve means having two-directional movement along itslongitudinal axis and being spring biased in one direction against saidinlet-exit port for charging said chamber with high pressure fluid, b.fluid pressure passage means for applying an equal force in both of saiddirections to said hollow elongated valve means so that a minimum forceis required to open said inlet-exit port, c. said hollow elongated valvemeans being movable rapidly in a second direction to open saidinlet-exit port suddenly for exhausting said high pressure fluidtherefrom, d. said hollow elongated valve means comprises a hollowelongated plunger slidably mounted in a housing containing said chamber,e. said hollow elongated plunger having equal and opposite areas normalto said longitudinal axis for said equal and opposite forces to beapplied thereto, f. said hollow elongated plunger comprising first andsecond hollow elongated elements having inner and outer ends, the innerend of said second element being secured in the inner end of said firstelement, g. a stud fixed to said housing and protruding therefrom intothe outer end of said first element, and h. a spring positioned in saidfirst element between said stud and said inner end of said secondelement for spring biasing said outer end of said second element againstsaid inlet-exit port for charging said chamber with high pressure fluid.2. A high pressure fluid supply and quick action valve assembly forcharging a chamber having an inlet-exit port supply passage means tosaid chamber and exhaust passage means from said chamber comprising, a.hollow elongated valve means having two-directional movement on itslongitudinal axis and being spring biased in one direction against saidinlet-exit port for charging said chamber with high pressure fluid, b.fluid pressure passage means for applying an equal force in both of saiddirections to said hollow elongated valve means so that a minimum forceis required to open said inlet-exit port, c. said hollow elongated valvemeans being movable rapidly in a second direction to open saidinlet-exit port suddenly for exhausting said high pressure fluidtherefrom, d. said fluid pressure passage means comprises a first fluidpassage through the length of said hollow elongated plunger means forpressurizing and charging said chamber, e. said hollow elongated plungermeans has equal and opposite areas normal to its longitudinal axis, f.said fluid pressure passage means comprises a second passage to saidequal and opposite areas on said hollow elongated plunger means forapplying equal and opposite forces longitudinally to said hollowelongated plunger means, g. said fluid prEssure passage means comprisesa third passage transversely through said hollow elongated plunger meansinterconnecting said first and second passages for charging andpressurizing said chamber, h. actuating means, i. said hollow elongatedplunger means being responsive to said actuating means for closing saidthird passage for stopping the flow of pressurized fluid to saidchamber, and j. said housing has stud means for closing said thirdpassage as said hollow elongated plunger means is moved in one of saidtwo directions on its longitudinal axis for stopping the flow ofpressurized fluid to said chamber.
 3. A high pressure fluid supply andquick action valve assembly as recited in claim 1 wherein, a. said fluidpressure passage means comprises a fluid passage to said equal andopposite areas on said hollow elongated plunger means for applying equaland opposite longitudinal forces to said hollow elongated plunger means.4. A high pressure fluid supply and quick action valve assembly asrecited in claim 1 wherein, a. the valve assembly has actuating means,and b. said hollow elongated plunger means is responsive to saidactuating means for opening said inlet-exit port for quick release ofpressurized fluid from said chamber.
 5. A high pressure fluid supply andquick action valve assembly as recited in claim 2 wherein, a. saidhollow elongated plunger means is responsive to said actuating means foropening said inlet-exit port for quick release of pressurized fluid fromsaid chamber.